Great article indeed and it was a pleasure talking with Ellen when she interviewed a number of us for this story.

One comment I'd like to make publicly is that the main issue I see is the lack of security controls between virtual machines. Yes, there are other problems such as the possibility to hijack another VM by jumping from one memory space to another but what about securing the virtual network?

Physical or Virtual we will always have a need to lock down and isolate communication between devices be it physical or virtual.

What is really missing from the solutions that are currently trying to address the security problems are VM to VM isolation. Most products that are Virtual Security products can still only see Virtual to Physical LAN communication and many will argue that this job is already being done by physical Firewalls and IPS devices.

John Peterson
Security Veteran
Blog: http://www.vmwaresecurity.com